VONA
What is VONA?

VONA stands for Volcano Observatory Notice for Aviation. It issues reports for changes, both increases and decreases, in volcanic activities, providing a description on the nature of the unrest or eruption, potential or current hazards as well as likely outcomes. See the following link (USGS) for further details. The Center for Volcanology and Geological Hazard Mitigation (CVGHM) under the Geological Agency of the Indonesian Ministry of Energy and Mineral Resources produced VONA's reports based on analysis of data from the agency's monitoring networks as well as from direct observations. VONA's alert levels are color-coded to indicate the different types of notifications addressing specific informative needs. The reports are disseminated via email to national and international stakeholders in the aviation sector. Other interested parties can avail of them through email subscription. All notifications are publicly available online.

USGS
 

2nd of May 2018, 2 years ago

2018-05-02 01:10:00 UTC Orange

Marapi - 20180502/0110Z 

Hartanto Prawiro, A.Md., Marapi Volcano Observatory - 2 years ago

Eruption with volcanic ash cloud at 0003 UTC (0703 Local Time). Eruption and ash emission is not continuing. Best estimate of ash-cloud top is around 72768 FT (22051 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. High Pressure and Dark Grey ash-cloud moving to southeast..

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4th of June 2017, 3 years ago

2017-06-04 09:24:00 UTC Orange

Marapi - 20170604/0924Z 

Hartanto Prawiro, A.Md., Marapi Volcano Observatory - 3 years ago

Eruption with ash clouds at 08:50 UTC (15:50 local time). The eruption lasted for 43 seconds. Best estimate of ash-cloud top is around 33168 FT (10051 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to east..

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2017-06-04 07:32:00 UTC Orange

Marapi - 20170604/0732Z 

Moh Nurul Asrori, A.Md., Marapi Volcano Observatory - 3 years ago

Eruption with ash clouds at 05:56 UTC (12:56 local time). The eruption lasted for 13 seconds. Best estimate of ash-cloud top is around 32640 FT (9891 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to east..

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2017-06-04 05:23:00 UTC Orange

Marapi - 20170604/0523Z 

Moh Nurul Asrori, A.Md., Marapi Volcano Observatory - 3 years ago

Eruption with ash clouds at 03:11 UTC (10:11 local time). The eruption lasted for 22 seconds. Best estimate of ash-cloud top is around 37920 FT (11491 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to east..

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2017-06-04 05:15:00 UTC Orange

Marapi - 20170604/0515Z 

Moh Nurul Asrori, A.Md., Marapi Volcano Observatory - 3 years ago

Eruption with ash clouds at 03:01 UTC (10:01 local time). The eruption lasted for 35 seconds. Best estimate of ash-cloud top is around 33696 FT (10211 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to east..

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VONA Color Code

Volcano is in normal, non-eruptive state, or, after a change from a higher level: Volcanic activity considered to have ceased, and volcano reverted to its normal, non-eruptive state.


Volcano is experiencing signs of elevated unrest above known background levels, or, after a change from higher level: Volcanic activity has decreased significantly but continues to be closely monitored for possible renewed increase.


Volcano is exhibiting heightened unrest with increased likelihood of eruption with column height below 6000 meter above sea level.


Eruption is forecast to be imminent with significant emission of ash with column height above 6000 meter above sea level.